Air filtration system

ABSTRACT

An air filtration system may monitor and control air quality within a building with the use of multiple housings strategically placed throughout the building. Each housing includes a motor driving a fan and an air filter. Selective activation of a cleaning mode removes particulates from the filter within each housing, cleaning only the air filter within the housing that requires cleaning. Air filter cleaning time and power consumed for cleaning is thereby reduced. Also, filtration is improved by locating a filter and a motor at key locations.

CROSS-REFERENCE TO RELATED APPLICATION AND PRIORITY CLAIM

This application claims the benefit of and priority to U.S. provisional application Ser. No. 62/074,929 filed Nov. 4, 2014, which is incorporated herein by reference for all purposes.

BACKGROUND OF THE INVENTION

The present invention relates in general to the field of industrial air filtration. More particularly, the present invention relates to a system that filters air of particulates and to a controller for said system.

It is well known in the field of industrial manufacturing that air quality within the facility is important. Airborne particulates can cloud the ambient air making it difficult to see, which can present a safety concern. Additionally, airborne particulates can be inhaled by employees causing many medical ailments, both temporary and permanent. As a result, ambient air within a manufacturing facility is commonly exchanged with outdoor air and also filtered.

With respect to air filtration, fans and filter media are commonly used. Typically a large, powerful motor is used to operate a fan. Ducting may also be piped from the fan to multiple worksites. The ambient air, along with any particulates generated, may then be sucked into the ducting and filtered with any known media.

A problem with this type of filtration is that the single fan requires a great deal of energy to operate. It is difficult to properly size the motor for the entire building as some locations, i.e. welding booths, require more filtration than others. The motor is commonly oversized and runs at a single high setting to ensure proper overall filtration is achieved. Some locations close to the fan may also be more effectively filtered as there is more suction in these areas. Pockets of “quality” air may then form with in the facility with pockets of polluted air in other areas of the facility.

What is therefore needed is a more efficient way to operate and size a fan motor for a manufacturing facility that includes multiples zones, each having unique filtration requirements. What is also needed is an improved way to control the motor so that it only consumes the amount of energy required to operate at a desired level. What is also needed is an improved air filtration system that can more effectively and more efficiently filter ambient air within a manufacturing facility

SUMMARY OF THE INVENTION

An air filtration system may include a first housing with an air filter configured to capture a plurality of airborne particulates. In order to flow the ambient air through the air filter, a motor may be employed within the first housing configured to power a fan and flow the ambient air through the first housing and air filter. A variable-frequency drive within the first housing may be configured to control speed and torque of the motor by varying the motor input frequency and voltage to the exact level required for optimized performance.

An air filtration control unit may be mounted within the first housing that may also be cooled by the air flow of the air filtration system. The air filtration control unit may be configured to activate and deactivate the filtration system based on a predetermined filter pressure. A first transducer in communication with the control unit may be configured to monitor air filter pressure. A second transducer may also be in communication with the control unit that is configured to control both motor rotations per minute (RPM) and the motor drive frequency based on sensed air filter pressure. To minimize/prevent damage in the event of a fire, a heat sensor in communication with the control unit may be configured to sense a fire and set an alarm. A smoke sensor may also be in communication with the control unit configured to sense weld smoke or other fire-related airborne particulates and stop the air filtration system based on sensed smoke levels.

A second housing in fluid communication with the first housing may be used to further add efficiency to the air filtration system. An air filter cleaning control unit may be mounted within the second housing that is programmed with an air filter cleaning mode configured to selectively stop the motor (or dramatically reduce the speed) within the first housing when the cleaning mode is activated. During cleaning mode, an access gate within the first housing may be configured to be selectively opened and closed by the air filter cleaning control unit in order to empty captured airborne particulates within the air filter. To assist in cleaning the air filter, a secondary motor, controlled by the air filter cleaning control unit in fluid communication with the first and second housing, may be configured to reverse a flow of air through the air filter thus releasing a plurality of particulates from the air filter through the access gate and into an appropriate receptacle. It may also be beneficial to clean into low pressure so as to create a continuous dust flow away from the filter, thereby reducing a portion or residual of the dust from returning back onto and into the filter as is caused by pulse resurgence or blower start up.

A master control unit may also be included and configured to communicate with and remotely manage the air filtration control unit and the air filter cleaning control unit. A plurality of lights may also be used in communication with the air filtration control unit and configured to indicate a status of the air filter with one of the following: a solid color indicating the air filter is in a healthy condition; a slowly flashing color indicating the air filter is close to requiring the air filter cleaning mode; and a quickly flashing color indicating the air filter is in a saturated condition and requiring the air filter cleaning mode. (Of course, other lighting schemes could be used.)

In order to be effectively implemented in any number of unique installations, the air filtration control unit may include a programmable logic controller configured to control a power distribution panel for supplying power to the motor, variable-frequency drive, and a first transducer. A network may also be established with cabling, or wireless, linking a plurality of first housing each with a motor and variable-frequency drive in communication with the air filtration control unit.

A plurality of motorized louvers may be controlled by either the master control unit or by any of the other control units and configured to direct a flow of exhaust air from the motor thus minimizing a contamination of a welding process. An air regulator in communication with the air filtration control unit may be configured to allow a remote monitoring of compressed air within the first housing. The air filtration control unit may also be configured to log and display a performance data in a graphical interface both on screen, on a touch-screen, saved to memory, printed, or transmitted to other systems.

These and other aspects and objects of the present invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention, is given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.

While certain possible applications and advantages of the present invention are described herein, many other applications are possible and references to use in connection with a particular application should not be deemed to limit the uses of the present invention. The terms used herein should not be interpreted as being limited to specific forms, shapes, or compositions. Rather, the parts may have a wide variety of shapes and forms and may be composed of a wide variety of materials.

BRIEF DESCRIPTION OF THE DRAWINGS

A clear conception of the advantages and features constituting the present invention, and of the construction and operation of typical mechanisms provided with the present invention, will become more readily apparent by referring to the exemplary, and therefore non-limiting, embodiments illustrated in the drawings accompanying and forming a part of this specification, wherein like reference numerals designate the same elements in the several views, and in which:

FIG. 1 illustrates an overhead perspective view of a pictorial representation of an air filtration system according to one embodiment of the invention including multiple first housings;

FIG. 2 illustrates a pictorial representation of an air filtration system according to one embodiment of the invention;

FIG. 3 illustrates a pictorial representation of an air filtration system according to another embodiment of the invention;

FIG. 4 illustrates a pictorial representation of the air flow within a facility equipped with the air filtration system of either FIG. 1 or FIG. 2;

FIG. 5 illustrates installed first housings according to FIG. 1 shown installed along a wall;

FIG. 6 illustrates a front view with a partial cross-section of a second housing, or housekeeping unit, as referenced by numeral 30 in FIG. 1;

FIG. 7 illustrates a perspective view of multiple second housings according to FIG. 1 installed in an outdoor environment; and

FIG. 8 illustrates a chart indicating representative examples of the possible energy savings resulting from a typical installation of the system.

In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific terms so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. For example, the words “connected,” “attached,” or terms similar thereto are often used. They are not limited to direct connection but include connection through other elements (including wireless communication) where such connection is recognized as being equivalent by those skilled in the art.

DETAILED DESCRIPTION

Beginning with FIG. 1, an air filtration system 10 is shown. The air filtration system 10 departs from traditional filtration as it employs a plurality of first housings 12 at each desired point of filtration. Points of filtration may include, but are not limited to, welding benches, grinding areas, machining centers, or any other area where dust and particulates may become airborne. For example, a manufacturing facility may have a welding booth on one end of the building and a paint booth at an opposite end of the building. A first housing 12 may be located at each one of the welding booth and paint booth. Within the first housing 12, are at least one air filter 14 and a motor 16 for powering a fan. A single master control unit 38 may be located anywhere in the building, or even remotely, and used to control each one of the first housings 12. The master control unit 38 communicates with an air filtration control unit 20 located within each one of the first housings 12. Each of the air filtration control units 20 controls the motor 16 within the first housing 12. The air filtration control unit 20 controls and modulates the motor 16 torque and drive frequency such that the motor 16 only consumes as much power as is needed to efficiently filter the area around the first housing 12.

In order to effectively control the motor 16, a variable frequency drive 18 is operably connected to the air filtration control unit 20 within each first housing 12. The variable frequency drive 18 makes it possible to modulate the power delivery to the motor. A first transducer 22 and a second transducer 24 are respectively located upstream and downstream of the air filter 14 and can determine the differential pressure. Once a predetermined threshold is reached, indicting the respective air filter 14 is sufficiently saturated, either one of the master control unit 38 and air filtration control unit 20 can power down the motor 16 powering that respective first housing 12. Once the motor 16 is powered down and sufficiently stopped (or dramatically reduced), either one of the master control unit 38 and air filtration control unit 20 moves an access gate 34 at the base of the respective first housing 12 opening an air passage to the housekeeping unit, also referred to as second housing 30. It may be beneficial to clean into low pressure so as to create a continuous dust flow away from the filter, thereby reducing a portion or residual of the dust from returning back onto and into the filter as is caused by pulse resurgence or blower start up. The second housing 30, shown in greater detail in FIG. 6, includes an air filter cleaning control unit 32 that communicates with the master control unit 38. The air filter cleaning control unit 32 activates a secondary motor 36 which pulls air through the air passage and through the air filter 14 within the respective first housing 12, and into the intake 54 of the second housing 30 ultimately to expel exhaust 56 either within the facility, preferably, with a HEPA filter 68, or to the exterior of the facility. This is done to evacuate the air filter 14 from the collected particulates. Air filters 52 may further filter particulates within the second housing 30. Particulate bins 58 may be placed to collect the captured particulates for proper disposal. FIG. 7 shows a pair of second housings 30 located on the outside of a facility.

In order to more efficiently clean the air filter 14, it is known to apply compressed air to the air filter 14 to blow out the particulates. The compressed air is commonly supplied at 90 psi and pulsed on and off for approximately an hour in a traditional unit. As the air filtration system 10 has the ability to clean out a single air filter 14 at a single first housing 12, the compressed air only needs to be supplied at 35 psi for approximately 12 seconds every three days. While the invention is not limited to exactly 35 psi for 12 seconds every three days, the invention drastically lowers both the pressure needed of compressed air as well as the duration and frequency of compressed air. This equates to significant savings in energy, reduced airborne contaminates, and also less noise pollution with the facility. FIG. 8 discloses a table of annual energy savings that are possible to achieve using a typical installation of the invention. The table is representative only and more or less savings may be achievable depending on the system configuration and facility. Such savings of energy are made possible by not only controlling the power consumed by the various motors, but also by cleaning the filters only as needed. This results in the removal of more contaminant but at drastically lower air pressures and durations. Typical installations of the prior art use a single, large motor that is either on or off The cleaning cycle is also performed at set times, usually daily, for a period of time up to an hour with 90 psi of air pressure to blow off the filters. The invention can be used to limit filter cleaning to a minimal time period, e.g., under twenty minutes, every couple of days with a much lower air pressure, e.g., 35 psi.

As mentioned, the air filtration system 10 locates any number of first housings 12 in any number of locations through the facility. Through communication among the master control unit 38, air filtration control unit 20, and air filter cleaning control unit 32, each air filter 14 within each first housing 12 can individually be cleaned when the pressure differential is sensed as reaching a predetermined threshold. Units of the prior art commonly have a single motor and a single fan that provide suction to a number of locations with ductwork. Filtration is used to filter particulates of the air. As a result, when a cleaning operation of the filters is performed, the air filtration for the entire plant is cleaned. This requires significant air pressure for a significant time. Also, the single motor must power a significantly larger fan. In stark contrast, the air filtration system 10, places smaller motors 16, smaller air filters 14 in any number of first housings 12 in key locations throughout the facility, likely near the contaminant source. Each individual first housing may independently be controlled to only run the motor 16 with the required power to efficiently filter the area. As each location throughout the facility has unique amounts of airborne particulates, the power consumed to filter these unique locations can be custom tailored, as opposed to a “one size fits all” as is done in the prior art.

The end result of tailoring the air filtration system 10 to meet the requirements of not only each individual facility, but also each individual zone within the facility, produces an end result of increased air filtration consuming less power and producing less noise. Employee vision and respiratory health may both be improved as there is a significantly reduced amount of airborne particulates within the facility as compared to air filtration of the prior art.

As an added safety improvement, the air filtration system may be equipped with a heat sensor 26 and smoke sensor 28 in each first housing. The heat sensor 26 and smoke sensor 28 can communicate with the master control unit 38 as well as the air filtration control unit 32 to alert personnel of a potential fire. The individual first housing 12 may also be deactivated to choke off the air supply to the potential fire. Alternatively, the entire air filtration system 10 may be shut down. As each first housing 12 is an independently operating system, the potential fire may be isolated to a single location, as opposed to a much greater threat of a fire in the single motor filtration system of the prior art.

Turning now to FIGS. 2 and 3, different ways of wiring the network wire 40 are shown. FIGS. 2 and 3 illustrate the master control unit 38 which includes a programmable logic controller (PLC) 60 as well as a power distribution panel 62. The variable frequency drive 18 may be located in either the master control unit 38 or within the air filtration control unit 20. The master control unit 38 may be wired with network wire 40 to communicate with the air filtration control unit 20 using pinned cables for quick and simple connectivity as shown in FIG. 2, or may be hard wired as shown in FIG. 3. In both FIGS. 2 and 3, the master control unit 38 communicates with the first transducer 22, second transducer 24, motor 16, access gate 34, heat sensor 26, and smoke sensor 28 within the first housing 12. The master control unit 38 may communicate, and ultimately control, the various components of the first housing 12 either directly as shown in FIG. 3, or through the air filtration control unit 20. The master control unit 38 may also be programmed to control and communicate with any amount of added relays, transducers, motors, and sensors. For example, lights 64 are shown in FIG. 2 which may flash to indicate the status of the air filtration system or the status of the respective first housing 12. The lights 64 may indicate status with a solid color indicating the air filter is in a healthy condition, a slowly flashing color indicating the air filter is close to requiring the air filter cleaning mode, and a quickly flashing color indicating the air filter 14 is in a saturated condition and requiring the air filter cleaning mode activated by the second housing 30 and air filtration cleaning control unit 32. Of course, other lighting arrangements or indicators could be readily used.

As previously mentioned, a plurality of first housings 12 may be located throughout a building 42 as shown in FIG. 4 as well as FIG. 5. Referring to FIG. 4, the first housings 12 may be equipped with louvers that are either manually controlled or controlled by the master control unit 38. The louvers may direct clean air flow 66 upward and away from work zones. Directing clean air flow 66 in such a manner pulls the particulates 46 upward and away from the work sites. Keeping the particulates 46 above the work sites also prevents inhalation by employees. The location of the first housings 12, as seen in FIG. 4, on both the roof and walls of the facility, maintain the air flow above breathing areas. Also, by mounting the first housings 12 on the walls and ceiling, the footprint of the entire air cleaning system is essentially zero. The second housing may also be kept outdoors, further eliminating precious floor space within the facility consumed by air filtration.

Additional first housings 12 located on a ceiling of a building 42 can further draw particulates 46 upward for proper filtration and direct clean air flow 66 downward. A roof vent 44 may also be used to exhaust air. With multiple first housings 12 strategically placed and strategically directing clean air flow 66, air currents may be formed within the building 42 that further assist in directing particulates 46 toward first housings 12 for filtration.

Another benefit of the air filtration system is that the vacuum or negative pressure commonly associated with air filtration is eliminated. In known installations, high levels of cubic feet per minute (“CFM”) are exhausted out of the facility. This creates a negative pressure within the building which can make doors hard to open and also cause doors to slam shut. Make-up air units are commonly installed to provide fresh air into the facility to make-up for the high levels of exhausted air. As the invention uses multiple motors in first housings 12 which are intelligently controlled, the CFMs needed to adequately filter the air are much lower than typically experienced with known air filtration devices. Make-up air units are resultantly not needed, which provides additional cost savings. Less airborne particulate matter is also exhausted to the outdoor environment as there is lower overall exhaust CFMs used, which is good for the neighboring environment. As less air is exhausted out of the facility, there is also energy savings from lower burdens placed on the climate control system. Air is also circulated well throughout the facility with the multiple first housings 12 which eliminate hot/cold zones from stagnant air. This not only provides climate control savings but also increases comfort levels experienced by the workforce.

Another advantage of the increased air filtration is that airborne particulates do not settle and accumulate on electrical devices. For example, computers and electrical equipment are commonly used in manufacturing environments. Airborne particulates commonly settle on objects and accumulate within the cooling systems of these computers. Over time, the buildup of particulates causes overheating in the computers and also commonly causes electrical shorts in facilities where the particulates include electrically conductive materials, i.e., metal dusts. By increasing the air filtration, computers and other electrical equipment lasts longer as they are allowed to remain within their operating temperatures. There is also less cleaning of settled particulate matter needed by maintenance staff, which provides additional savings.

Although the best mode contemplated by the inventors of carrying out the present invention is disclosed above, practice of the present invention is not limited thereto. It will be manifest that various additions, modifications, and rearrangements of the features of the present invention may be made without deviating from the spirit and scope of the underlying inventive concept. Moreover, the individual components need not be formed in the disclosed shapes, or assembled in the disclosed configuration, but could be provided in virtually any shape and assembled in virtually any configuration. Further, although the air filtration control unit 20, air filter cleaning control unit 32, and master control unit 38 described herein are physically separate modules, it will be manifest that they may be integrated into a single controller. Furthermore, all the disclosed features of each disclosed embodiment can be combined with, or substituted for, the disclosed features of every other disclosed embodiment except where such features are mutually exclusive. It is intended that the following claims cover all such additions, modifications, and rearrangements. 

We claim:
 1. An air filtration system comprising: a first housing with an air filter configured to capture a plurality of airborne particulates; a motor associated with the first housing configured to flow an ambient air through the first housing and air filter; a variable-frequency drive configured to control a speed of the motor by varying a motor input frequency or a voltage; an air filtration control unit configured to activate and deactivate the air filtration system based on a predetermined filter pressure and control the motor based on a sensed air filter pressure; a first transducer in communication with the air filtration control unit configured to monitor air filter pressure; and a second transducer in communication with the air filtration control unit configured to monitor air filter pressure;
 2. The air filtration system of claim 1, further comprising: a second housing in fluid communication with the first housing; an air filter cleaning control unit associated with the second housing; an air filter cleaning mode programmed into the air filter cleaning control unit and configured to selectively stop the motor associated with the first housing; an access gate associated with the first housing configured to be selectively opened and closed by the air filter cleaning control unit; and a secondary motor controlled by the air filter cleaning control unit in fluid communication with the first and second housing configured to reverse a flow of air through the air filter thus releasing a plurality of particulates from the air filter through the access gate.
 3. The air filtration system of claim 2, further comprising: a heat sensor in communication with the air filtration control unit configured to sense a fire and activate an alarm or stop the air filtration system based on sensed heat levels; and a smoke sensor in communication with the air filtration control unit configured to sense smoke or fire-related airborne particulates and activate an alarm or stop the air filtration system based on sensed smoke levels.
 4. The air filtration system of claim 2, further comprising a master control unit configured to communicate with and remotely manage the air filtration control unit and the air filter cleaning control unit.
 5. The air filtration system of claim 1, further comprising a plurality of lights in communication with the air filtration control unit and configured to indicate a status of the air filter.
 6. The air filtration system of claim 1, wherein the air filtration control unit includes a programmable logic controller configured to control a power distribution panel for supplying power to the motor, variable-frequency drive, and first transducer.
 7. The air filtration system of claim 1, further comprising a network linking a plurality of first housings each with a motor and variable-frequency drive in communication with the air filtration control unit.
 8. The air filtration system of claim 1, further comprising a plurality of motorized louvers configured to direct a flow of exhaust air from the motor.
 9. The air filtration system of claim 1, further comprising an air regulator in communication with the air filtration control unit configured to allow a remote monitoring of compressed air within the first housing.
 10. The air filtration system of claim 1, wherein the air filtration control unit is configured to log and display performance data in a graphical interface. 